Two-phase flow structure of sheet cavitation

An experimental study of flow within sheet cavities is performed in a cavitation tunnel equipped with a Venturi-type test section. The flow is investigated by means of a double optical probe allowing void fraction, velocity, and chord length of the vapor structures to be measured. Laser velocimetery, wall pressure measurements, and visualization techniques are also used to characterize the liquid flow around the cavity. The consistency of the experimental results was checked though mass and momentum balances. The effects of Reynolds and cavitation numbers are analyzed. Special attention is given to the dynamic behavior of the flow, and to the vapor flow rate within the cavities. The measurements show a complex two-phase flow characterized by the presence of an extended reversed flow occurring along the solid surface and a regular decrease in void fraction along the cavity. The phase transitions seem to be mainly restricted by the dynamic of the bubbles and thermodynamic effects.

[1]  D. F. de Lange,et al.  On the Mechanism of Cloud Cavitation - Experiment and Modelling , 1994 .

[2]  Isao Kataoka,et al.  Turbulence structure of air-water bubbly flow—I. measuring techniques , 1975 .

[3]  Philippe Dupont,et al.  Generation mechanism and dynamics of cavitation vortices downstream of a fixed leading edge cavity , 1988 .

[4]  O. C. Jones,et al.  Development of a k-ε Model for Bubbly Two-Phase Flow , 1994 .

[5]  J. Franc,et al.  Partial Cavities: Global Behavior and Mean Pressure Distribution , 1993 .

[6]  Optical probe for high-temperature local void fraction determination. , 1982, Applied optics.

[7]  A. Cartellier.  Optical probes for local void fraction measurements: Characterization of performance , 1990 .

[8]  R. Welle,et al.  Void fraction, bubble velocity and bubble size in two-phase flow , 1985 .

[9]  O. C. Jones,et al.  3-D turbulence structure and phase distribution measurements in bubbly two-phase flows , 1987 .

[10]  J. Delhaye,et al.  Void Fraction and Vapor and Liquid Temperatures: Local Measurements in Two-Phase Flow Using a Microthermocouple , 1973 .

[11]  D. K. Edmonds,et al.  Cavitation in Liquid Cryogens , 1969 .

[12]  François Danel.  Mesure locale dans les coulements diphasiques : dveloppements rcents des sondes optiques , 1978 .

[13]  J. Reboud,et al.  Experiments on unsteady cavitation , 1997 .

[14]  A. Cartellier,et al.  Local phase detection probes in fluid/fluid two‐phase flows , 1991 .

[15]  R. P. Benedict,et al.  ASME Measurement Uncertainty , 1985 .

[17]  Christopher E. Brennen,et al.  Observations of the dynamics and acoustics of travelling bubble cavitation , 1991, Journal of Fluid Mechanics.

[18]  N. Abuaf,et al.  Optical probe for local void fraction and interface velocity measurements. , 1978, The Review of scientific instruments.

[19]  Masatsugu Maeda,et al.  Unsteady Structure Measurement of Cloud Cavitation on a Foil Section Using Conditional Sampling Technique , 1989 .

[20]  J. Reboud,et al.  Impact of Vapour Production and Cavity Dynamics on the Estimation of Thermal Effects in Cavitation , 1996 .

[21]  A. Cartellier.  Local velocity and size measurements of particles in dense suspensions: theory and design of endoscopic grating velocimeter-granulometers. , 1992, Applied optics.

[22]  S. H. Park,et al.  The Splitting of Drops and Bubbles by Turbulent Fluid Flow , 1973 .

[23]  D. J. Gunn,et al.  The measurement of bubble flows in fluidized beds by electrical probe , 1985 .